Known RF (Radio Frequency) MOS (Metal-Oxide-Semiconductor) switches are based on a comb type layout. In this layout, the switch includes a gate that has a plurality of interconnected fingers. The fingers are interspersed with source and drain regions comprising elongate strips. Metal interconnects are provided to each source and drain region through a series of vias located at several points along each strip. Generally, the connection to the gate as made at one side of the device, at a common strip that interconnects each finger of the comb. The device may be surrounded by deep trench isolation (DTI).
Losses within such a switch may be relatively high. For instance, the isolation provided by the DTI surrounding the device does not affect substrate impedance within the device. Also, connection to the source and drain regions is relatively difficult, and can require connections having relatively high electrical resistance to be used.
Scaling of such a device is also limited to adding additional fingers to the comb or by varying the length of the fingers.